/*
 * Copyright 2012-2020 the original author or authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.data.couchbase.core.mapping.event;

import org.springframework.beans.factory.ObjectFactory;
import org.springframework.context.ApplicationListener;
import org.springframework.data.auditing.AuditingHandler;
import org.springframework.data.auditing.IsNewAwareAuditingHandler;
import org.springframework.data.mapping.context.MappingContext;
import org.springframework.util.Assert;

import java.util.Optional;

/**
 * Event listener to populate auditing related fields on an entity about to be saved.
 *
 * @author Oliver Gierke
 * @author Simon Baslé
 * @author Mark Paluch
 */
public class AuditingEventListener implements ApplicationListener<BeforeConvertEvent<Object>> {

  private final ObjectFactory<IsNewAwareAuditingHandler> auditingHandlerFactory;

  /**
   * Creates a new {@link AuditingEventListener} using the given {@link MappingContext} and {@link AuditingHandler}
   * provided by the given {@link ObjectFactory}.
   *
   * @param auditingHandlerFactory must not be {@literal null}.
   */
  public AuditingEventListener(ObjectFactory<IsNewAwareAuditingHandler> auditingHandlerFactory) {
    Assert.notNull(auditingHandlerFactory, "IsNewAwareAuditingHandler must not be null!");
    this.auditingHandlerFactory = auditingHandlerFactory;
  }

  /*
   * (non-Javadoc)
   * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
   */
  public void onApplicationEvent(BeforeConvertEvent<Object> event) {

    Optional.ofNullable(event.getSource())//
            .ifPresent(it -> auditingHandlerFactory.getObject().markAudited(it));
  }
}
